navigate Without Gps Map Compass - map And Compass - Photo 09

8. Bad idea: A steel hood will affect a magnetic compass. Even if you've got a fiberglass hood, there's a possibility that steel parts under the hood will throw off the reading. It's best to hold the compass in your hand or lay the map and compass on the ground. If there's enough iron in the soil, that too can throw off the reading - a rare situation, but a reality nonetheless.